Enable scala compiler.
updated compiler

@see http://stackoverflow.com/questions/13680729/is-this-the-latest-version-of-the-maven-scala-plugin
moved scala sources
Save original java sources
implments -> extends
use val/var
fix
fixed syntax
fixed variable declaration
renamed variable which has name similar to keyword
get rid of static import
fixed variable declaration
Deleted Java files which conflicts with scala sources
configure compiler